Electrical furnace.



A. EIMER.

ELECTRICAL FURNACE.

APPLICATION F1LD1uLY18.1914.

1 1 97,275 Patented Sept. 5, 1916.

12 'M mlm i .f [12:22:22:::11:22:21::IIE? 1,; 7 Z ,i f, i5 1a' la; ift e oec: gwen/Lto@ 35161 om, 2

AUGUST EIMEB, 0F NEW YORK, N. Y.

ELECTRICAL FUBNACE.

Specification of Letters Patent.

Patented Sept. 5, 1916.

Application led July 18, 1914. Serial No. 851,703.

versal inits operative arrangement, kto present, on one sidey exposed heatmg conductors sunk 1n grooves and directed toward the,`

furnace interior, and when reversed to present to the furnace interior a smooth, unbroken surface completely. covering the heating conductor.

The material of which the heating units are formed is of such a character as to withstand the action of heat and at the same time has the property of conducting heat, to readily communicate the heat it receives tothe furnace interior; also being a non-conductor of electricity, to insulate the conductor lengths which are spaced apart in said heating units. As examples of such material I may refer to fused, semi-fused and calcined alumina, magnesia and zirconia, silica, porcelain and quartz.

The heating units, which are radapted to protectingly `contain the telectrical conductors, are so constructed that they fit removtogether tol formthe inclosing interior walls of the muffler-or furnace, in such manner that` any. one or lall" ofthe` unitv plates forming the sides, top `and bottom thereof, may conveniently be removed and reversed,

'q thereby providing for `the instant adaption of the furnace or muflle for any desired character of work. The heating members or plates, which have parallel, sunken grooves in one surface ytocontain a conductor in nonextruding relation, have alternateopposite end portions receed to contain the looping portion of the conductor in turning into the next adjacent grooves, to prevent extrusion of said conductor at the ends of the heating member.

one form of my improved furnace or mufe showing the side, top and bottom reversible heating units and their manner of removable placement. Fig. 2 is a similar view of a furnace with arched top removable or swinging open upon a hinge. the top portion having means supporting the upper heating unit independently of the lower portion of the furnace. Fig. 3 is a similar view of a furnace corresponding to that shown in Fig. 2 excepting that the span of the upper section is of greater extentlthan the span of the lower section to contain the increased girth vof vessels llike crucibles which haveA a greater diameter `at'the ltop than at` the bottom.. Fig. 1i is a similar view of a furnace provided with heating sections at each of its six sides. Fig. 5 is a detail plan view of a heating member. Fig. 6 is a fragmentary side elevation to show binding posts for the conductor terminals, and Fig. 7 is a section through the front cover for the furnace shown in Fig. 1.

Referring lirst to that form of my invention shown in Fig-1 the housing of the furnace will be seen to consist of the side walls 1, end 2, top 3, base 4, and removable front cover 5, (Fig. 7). This housing is composedy of `suitable material of low thermal conductivity, which will conserve the heat generated within the furnace and retard its convection. The baseV heating member 7 has its opposite side portions 8 reduced, by recessing them on both surfaces. The side heating members 9 are rectangular in cross' section and stand vertically upon the reduced portions of thebase heatingmember 7, and the upper heating member 10 rhas reduced side portions 11 which fit upon thetopsof members 9t to supportsaid member 10.

'Ihe side walls-'1 of the furnace are notched'y longitudinally at their upper portions, as at 12, and at their lower portions, asv at 13, to respectively receive the rojecting ends of the upper and lower eating members. It will be observed that said upper and lower heating members are interchangeable, and are also reversible, the same being true of the opposite side heating members. Further that the side heating members may be removed without disturbing the upper heating member, which, without their support, remains lodged in the notches 12. Obviously the lower notches 13 render possible the interchangeable character of the upper and lower heating members.

Each heating member is provided on one surface with a series of parallel grooves 14 for a resistance conductor, which may be in form of a spiral Wire, 0r of other desirable character. These grooves have relatively narrow ventrance slots to prevent extrusion of the conductor, and the divisional walls between adjacent grooves are successively shortened at opposite ends, as at 15, to allow the conductor to turn from one groove end into the next groove to avoid exposing the conductor beyond the end of the heating member. The opposite terminals from each heating member may be passed through orifices in the rear Wall of the furnace and there connected in any desired series or parallel electrical arrangement, as to binding posts 16.

When the heating members are arranged in the furnace in `the manner shown in Fig. 1 with their open groove surfaces facing inwardly the furnace Will be useful for .certain purposes as Where lquicker heat is re-Y quired, or one or more of said heating members may be so placed and the other members arranged with their opposite or closed smooth surfaces facing inwardly, or, if `desi-red, all the heating members vmay be reversed to present to the furnace interior the closed smooth surfaces of all the heating members.

It will be readily understood, in the great variety of uses to which the heat of the f-urnace may be applied, `that the ability to` promptly transform the heating members, or some of them, by reversal from exposedl conductor heaters to plain heater Walls, and vice versa, largely extends 4the Vvrange of usefulness of the furnace. A particular instance Where it is undesirable to present exposed conductors to the vfurnace is Where ,the material being ,heatedl evolves fumes deleterious in their action upon the conductors; further where directly radiated heat would prove ,injurious to fine edged steel cuttin tools.

In Fig. 2 is shown an example of my im proved furnace wherein thehousing 17 is `provided with an arched cover 18, Which may behinged to said housing, as at 19. The arched cover 18 is provided with an annular fiange'20, detachably connected there to, at its base, and extending inwardly beyond kthe inner perimeter of said base, to support a concave-convex heating member 21. The member 21 not being vreversible must. be constructed specially with either-ex,- posed or covered conductors.v

The furnace shown in Fig. 3 may correspond in all essentials with that just described excepting that the maximum transverse interior larea of its heating member 22 may exceed the transverse area of the heat- Copies o! this patent may be obtained for ing member 23 in the housing, which it incloses, in that manner accommodating a ves-l sel whose upper portion is larger in girth than its loiver portion, without leaving a greater 4clearance between thc 'heating members and the vessel than is necessary, thereby permitting the 'heating surfaces to be equally effective over all portions of the vessei Whose ycontents are being heated, Which vessel maybe a crucible.

In Fig. 4 `I have show-11 a furnace in rectangular form whose four walls are provided with heating members 24, lalso jhaving a `base heating member 25 and an upper heating member 26, which may be removed independently .or with the top 27, the forward Wa-llland heating member `hoW-ever not appearing in the` front sectional View shown.

Variations may be made Within the spirit and scope of the invention, and parts thereof may be used Withoutothers.

vI claim:

1. A yfurnace or muiile provided with electrical heating, reversible members in opposed spaced relation therein, said members each having a series of parallel exposed grooves .on one side to ycontain a resistance conductor, with inset notches alternating at,

opposite lends betweenadjacent4 grooves to carry the conductor from one groove to an` other, the opposite sideof said members provided with ,a smooth, conductor covering heating surface, and said members having interlocking edges vEfor their engagement' when said `members are arranged with either surface `presented to the furnace interior.

2. A furnace or muiiie provided With electrical `heating members in opposed, spaced relation therein, said members being reversible to present either surface thereof to the furnace interior, and said members having interlocking edges for their engagement when said membersare arranged with either surface presented to the furnace interior.

3. A furnace ormuffle provided With interchangeable, electrical heating members in opposed spaced relation therein, said members being reversible to present either surface thereof to the furnace interior, and said members having interlocking .edges for their engagement when said members are arranged With either surface presented toy the` furnace interior. y

Signed vat the borough of Manhattan in the city, county and State ofNew York this I/Vitnesses:

` EDWIN L. SMALLEY,

I". W. BARKER.

vc'cents each, by addressing the Gommissioner ot latenti, Washington, ZD. C. 

